Induction type alternating current relay



May 21, 1957 w. H. REICHARD INDUCTION TYPE ALTERNATING CURRENT RELAYFiled Oct. 25, 195:5

3 Sheets-Sheet 1 FIG-1.

. JNVENTOR. WHREICHARD BY HIS ATTORNEY May 21, 1957 w. H. REICHARDINDUCTION TYPE ALTERNATING CURRENT RELAY 3 Sheets-Sheet 2 Filed Oct. 25.1953 Fla mm mH m E R H W HIS ATTORNEY May 21, 1957 w. H. REICHARD2,793,266

INDUCTION TYPE ALTERNATING CURRENT RELAY Filed 001'.- 23, 1953 3Sheets-Sheet 5 Fla. 5. LINE 8 IBXI IIIOxI II '::9 I2

I J 5 E I PB I ii I L (CX) IIBxI LOCAL DIRECTION OF F I a ROTATIONTORQUE FLUX FROM END CORE LOCAL WINDING FLUX FROM END CORE T -T LOCALWINDING I FLUX FROM CENTER COR E LINE WINDING FLUX FROM CENTER CORE LINEWINDING INDUCED CURRENT NT R. g WH REI O II AIIO HIS ATTORNEY UnitedStates Patent INDUCTION TYPE ALTERNATING CURRENT RELAY Wade H. Reichard,Rochester, N. Y., assignor to General Railway Signal Company, Rochester,N. Y.

Application October 23, 1953, Serial No. 387,991

1 Claim. (Cl. 200-91) This invention relates to induction typealternating current relays, and more particularly pertains to a quickacting induction type relay adapted as a code following relay.

One of the objects of the present invention is to provide an inductiontype alternating current relay wherein an operating torque is providedwhen the two phase windings are supplied with alternating currents whichare substantially in phase.

Another object of the invention is to provide a relay of this type whichis quick acting in its response so as to be able to follow the usualcode rates employed in coded track circuits in connection with railwaysignalling.

A further object of the present invention is to provide a relaystructure in which the magnetic field that inductively produces thecurrent in the rotor will be entirely free from air gaps to make forefi'icient operation of the rotor positioned so as to move in an air gapin the other magnetic field.

Another object of the present invention is to provide a core structurewhich will serve two magnetic fields without being magnetically coupled.

Other objects, purposes and characteristic features of the presentinvention will be in part obvious from the accompanying drawings, and inpart pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to theaccompanying drawings, in which like reference characters designatecorresponding parts througl out the several views, and in which:

Fig. 1 is a top view of a structure forming a relay embodying thepresent invention;

Fig. 2 is a side view of the structure shown in Fig. 1 with parts shownin section as taken on line 2-2 of Fig. 1;

Fig. 3 is an end view of the structure shown in Fig. 1;

Fig. 4 is an isometric exploded view to diagrammatically illustrate theassociation of the rotor and magnetic structure;

Fig. 5 is a diagrammatic View to show the connections of the windingsfor operation of the relay;

Fig. 6 is a diagrammatic view with arrows and legends to indicate thedirection of the flux, currents and torque when the applied energy is ina rising positive quadrant; and

Fig. 7 shows the laminations in an isometric view of a consolidatedmagnetic structure as a modified form of the invention.

For the purpose of simplifying the illustration and facilitating in theexplanation, the various parts of the relay embodying the presentinvention have been shown in their relative positions and functionalrelationships without making any effort to illustrate the most refinedform both as to appearance and as to economical manufacture. Also, thefunctional characteristics have been illustrated without an effort toshow the best form to accomplish those functions. For example, thebearings of the relay are shown as having a form which is functionallycomplete, but which in a commercialized structure may assume some formof frictionless hearing or the like.

2,793,266 Patented May 21, 1 7

In the diagram of Fig. 5 indicating the circuits, symbols (BX) and (CX)are employed to indicate the opposite terminals of a suitablealternating current source, and these designations represent theterminals as having a particular relative instantaneous phaserelationship, the terminal (BX) being positive with respect to (CX).ltis to be understood that the different pairs of terminals may besupplied with energy from the same source or from different sources solong as the currents from the two sources are substantially in phasewith each other.

With reference to Fig. 1, it will be noted that the relay structure ismade up of two stackings A and B of laminations each of which is in aform which can be more readily seen in Fig. 4, and which has a form of afigure S-shape. These two stackings A and B are held together by upperand lower frame bars 5 and 6 (see Fig. 3) which are fastened along thesides of the stackings by bolts 7. These bolts 7 also hold in positionthe supporting legs 8 which are located at opposite ends of the relaywith extending feet as shown in Figs. 1 and 3 for fastening the relay toa suitable base.

Similar frame bars 13 and 1 are mounted above and below the stackings attheir centers to which bearing supports 18 are fastened by suitablebolts.

it is, of course, understood that the stackings are assembled in amanner to include the coils 9, it), 11 and 12 which are connected in amanner shown in detail in Fig. 5. Each of these coils is provided withsuitable L-shaped brackets 23 for holding them in their respectivepositions.

Referring to Fig. 2, it will be noted that a rotor 15 is formed in aU-shape with a cross member 15:: enclosing it. These two portions 15 and15:: are shown in the illustration as being bolted together; but it isto be understood that they could be welded or brazed together in anysuitable manner so as to make a completely closed electrical circuit.The rotor 15 is pivotal! mounted by having two bearing screws 17 fittinwithin the bearing supports 13 that are bolted to the laminatedstructure. Lock nuts 19 are employed to hold these bearing screws 17 inposition after they have once been set.

The right-hand end of the rotor 15 (see Fig. 2) has attached to it acontact operator 2t) which includes a slot 21 (see Fig. 3) for receivingthe extending spring 22 of a contact assembly.

This contact assembly comprises a support bracket 25 to which is mountedback contacts 26 and 27 respectively on opposite sides of the contactoperator 22 and the movable contact member 28. Suitable insulatingspacers 29 are employed, so that separate electrical connections may bemade to the back and front fixed contacts 26 and 27 and to the movablecontact 28. A toggle spring member 30 is located between the contactoperator Z2 and the movable contact spring 23 in such a way that thecontact operator 22 is normally biased to the position shown, and thiscauses the rotor 15 to assume the osition shown with the contactoperating member 2d acting to limit the rotor movement as it comes incontact with the stop member 31. When the rotor 15 is actuated to anoperated position by the application of energy, it movescounterclockwise as viewed in 1 so that the contact operating member it?touches the stop member 32. These stop members 31 and 32 are mounted onthe top plates 5 by the same bolts that hold the members 23 so that thestop members extend upwardly as shown in Fig. 3.

Although the use of the toggle spring 30 makes the contact operation ofthe snap-acting type, it is to be understood that other forms of contactstructure may be employed if desired. Also, the bias to the normalposition of the rotor 15 is in the main provided by the deformation inthe contact operating arm 22; but it is to be understood that otherarrangements of biasing means could be employed if desired.

Referring to Fig. 5, it will be seen that the windings 9 and 10 areconnected in series with the wires extending to the line which isconnected to the opposite terminals (BX) and (CX) of the source. Inorder to discuss the operation, without considering the specific waysthe line may be controlled, a push button PB has been indicated as beingin series in this circuit. This push button PE, or any suitable contactsmay be manually or automatically operated to intermittently, or atwhatever times desired, close the line circuit.

The coils 11 and 12 are connected in series and to a local source ofenergy having terminals (BX) and (CX) as indicated. It is noted that thewindings 9 and 10 when energized, as by closure of contact PB, causeelectromagnetic flux to circulate in the two independent magneticcircuits A and B. Since these windings are connected in series, the fiuxproduced by one is in the same direction as the flux produced by theother and when the upper terminal of coil 9 is connected to the terminal(BX) and the lower terminal of coil 10 is connected to the terminal(CX), the rising current for a positive half cycle causes flux to flowin a clockwise direction in the right-hand magnetic circuit and in acounterclockwise direction in the left-hand magnetic circuit. This fluxflowing in the directions indicated passes around the right andleft-hand vertical legs of the rotor 15 as indicated in Fig. 6. Thisinduces a circulating current in the rotor 15 having the directions ofthe arrow 35. The induced potentials in the vertical legs of the rotorare, of course, additive so these currents circulate in the samedirection.

Assuming that the potential applied to the local windings 11 and 12 hasthe relative instantaneous polarities indicated, then the currentflowing in windings 11 and 12 is in a direction to cause the flux torise in its respective portions and in phase with the rise of currentinduced in the rotor 15. The flux produced by these coils 11 and 12 isin the same direction, and the reaction forces between this flux and thecurrent flowing in the rotor is such as to produce opposite directionsof torque as indicated in Fig. 6, because the direction of current floware opposite in the two vertical legs of the rotor. This givescounterclockwise rotation to the rotor and actuates its against the stop32 and in so doing the movable contact operator 22 is actuated to closethe front contacts 26-28.

When the push button or contact PB is opened and energy is removed fromwindings 9 and 10, no current is induced in the rotor 15 and it isrestored to its normal position with member against the stop 31 byreason of 4 the biasing spring action of the contact assembly.

In the above discussion, it has been stated that the current flowing inthe local and line windings should be substantially in phase. In thisconnection, it should, of

course be recognized that the current induced in the closecircuitedrotor 15 will lag the potential applied to the line windings 9 and 1b acertain amount depending upon the values of the various component partsof the relay. However, since the rotor 15 is a single short-circuitedturn this lagging of the current is kept at a minimum. For this reason,there is a substantial torque produced in the relay when the local andline windings are supplied with potentials exactly in phase; but it isto be understood that the currents from these potentials may be shiftedwith respect to each other by suitable well known means so as to causethe induced current in the rotor to be exactly in phase with the fluxproduced by the current local windings 11 and 12. When these conditionsare present, the maximum torque per ampere of energization is, ofcourse, produced.

If the instantaneous relative polarities are exactly reversed, anytorque that is produced merely holds the rotor 15 more firmly againstits stop member 31 and no actuation of the contacts is effected.

Even though the structure shown and described above is assumed to haveseparate iron laminae to make up the two stackings A and B, it is to beunderstood that these two stackings may be combined in a singleconsolidated stacking, if desired for structural strength andconvenience in manufacture. It is possible to have the magneticinterconnection between the two ends of the relay because the coils 11and 12 produce flux in the same direction. In effect, the commonportions of the two stackings is at the center point of a bridge insofaras the flux circulating in the two paths is concerned, and for thisreason the operation of the relay is exactly the same with thismodification of its structure. Undoubtedly in a commercialized structurethis form would be desirable to give added mechanical strength andsimplify the manufacture; but the structure shown and discussed abovewhere the two stackings are magnetically independent merely emphasizesthe independence of the magnetic circuits and the operability of therelay. For the purpose of making clear this modified form of theinvention, Fig. 7 shows a consolidated form of stacking of laminae togive the desired mechanical strength.

Having thus shown two forms of alternating current relay of theinduction type as embodying the present invention, it is desired to beunderstood that these forms are selected to facilitate in the disclosureof the invention rather than to limit the number of forms which it mayassume; and, it is to be further understood that various modifications,adaptations and alterations may be applied to the specific form shown tomeet the requirements of practice, without in any manner departing fromthe spirit or scope of the present invention.

What I claim is:

In an alternating current relay structure, two separate stackings ofsoft iron laminate each having a figure 8 shape, said two stackingsbeing placed with corresponding sides of their figure 8 shape injuxtaposition, a winding being placed around the adjacent sides of saidtwo stackings, frame bars each being secured to both said stackings tohold them in position relative to each other, each of said figure 8shaped stackings having an air gap in the cross portions thereof, awinding on said cross portion of each of said stackings, a box-shapedrotor of nonmagnetic electrically conductive material being pivotallypositioned by said frame bars with its vertical side portions extendingthrough said air gaps, said windings on said cross portions beingarranged in series and with such relative polarity that when energizedthe resulting magnetic field passes through both said air gaps in thesame direction, circuit means for connecting said series-connectedwindings on the cross portions to a first source of alternating current,circuit means for selectively energizing said windings on the commonportion of said stackings to a second source of alternating current ofthe same frequency as said first source when it is desired to actuatesaid relay, snap acting contact means being associated with said rotor,said contact means normally biasing said rotor to a particular positionwhen said windings are deenergized, said rotor and said contact meansbeing actuated to their opposite positions when said windings on thecommon portion are energized with alternating current.

References Cited in the file of this patent UNITED STATES PATENTS1,470,566 Hailes Oct. 9, 1923 1,525,697 Stoekle Feb. 10, 1925 2,053,619Gofi Sept. 8, 1936 2,114,829 Bostwick Apr. 19, 1938 2,134,956 Scheg Nov.1, 1938 2,300,886 Goldsborough et a1 Nov. 3, 1942 2,301,162 Hoard Nov.3, 1942 2,345,440 Warrington Mar. 28, 1944 FOREIGN PATENTS 148,170Switzerland Sept. 16, 1931 545,903 Germany Mar. 7, 1932

